Why Enterprises Are Leaving Oracle for PostgreSQL

Let’s face it: legacy Oracle databases are becoming a costly anchor. Between rising licensing fees, hardware refresh cycles, and the need for niche DBA expertise, many organizations spend the majority of their IT budget just keeping the lights on. Meanwhile, agility and innovation take a back seat.

PostgreSQL, on the other hand, offers a compelling alternative. It’s open source (no licensing fees), highly extensible, and has a vibrant community. When combined with Azure’s managed services, it becomes a platform that can scale to meet even the most demanding enterprise workloads.

But migration is never trivial. Concerns about downtime, compatibility, and retraining are real. That’s why Microsoft has invested heavily in making the transition as smooth as possible. From AI-assisted migration tools to performance-optimized infrastructure, the path from Oracle to PostgreSQL on Azure is now clearer than ever.

The Hidden Cost of Staying Put

  • Escalating licensing fees: Oracle’s licensing model is notoriously complex and expensive.
  • Performance bottlenecks: On-premises hardware can’t keep up with modern data demands.
  • Scalability limits: Scaling Oracle vertically is expensive; horizontal scaling is even harder.
  • Innovation gap: Teams spend more time maintaining than building new features.

"Staying on legacy infrastructure might feel like a safe choice, but it’s rarely the best one." — Microsoft Engineering Team

Real-World Proof: Apollo Hospitals Case Study

Apollo Hospitals, one of Asia’s largest healthcare providers, faced exactly these challenges. With over 74 hospitals and 10,000 beds, their in-house hospital information system—built on Oracle—was becoming a bottleneck. Performance issues were impacting patient care, and costs were spiraling.

They made the bold decision to migrate to Azure Database for PostgreSQL. The results speak for themselves:

  • 90% of transactions complete within 5 seconds — a massive improvement in responsiveness.
  • Uptime increased to 99.95% — critical for hospital operations.
  • Deployment timelines dropped by 40% — faster feature rollouts.
  • 60% reduction in operational costs.
  • 3x improvement in overall system performance.

This isn’t just a tech upgrade; it’s a business transformation. Apollo is now exploring AI-powered dashboards, real-time analytics with Microsoft Fabric, and containerized workloads on AKS.

AI-Assisted Oracle-to-PostgreSQL Migration Tool

One of the biggest pain points in migration is converting Oracle-specific schemas, stored procedures, and application code. Manually rewriting thousands of lines of PL/SQL, Java, or .NET is error-prone and expensive.

Microsoft’s answer? An AI-assisted migration tool (now in preview) integrated into the PostgreSQL extension for Visual Studio Code, powered by GitHub Copilot.

How It Works

  1. Schema Analysis: The tool analyzes Oracle schemas and stored procedures.
  2. Automated Conversion: It converts them to PostgreSQL-compatible formats using intelligent pattern recognition.
  3. Application Code Refactoring: It updates database drivers, rewrites SQL queries, and modifies stored procedure calls in Java, .NET, etc.
  4. Unit Test Generation: Automated tests validate the converted logic.
  5. Post-Conversion Validation: Runs in a scratch PostgreSQL environment to check functional parity.
-- Original Oracle procedure
CREATE OR REPLACE PROCEDURE get_employee_salary (emp_id IN NUMBER) IS
  salary NUMBER;
BEGIN
  SELECT emp_salary INTO salary FROM employees WHERE emp_id = get_employee_salary.emp_id;
  DBMS_OUTPUT.PUT_LINE('Salary: ' || salary);
END;

-- Converted PostgreSQL function
CREATE OR REPLACE FUNCTION get_employee_salary(emp_id INT)
RETURNS VOID AS $
DECLARE
  salary NUMERIC;
BEGIN
  SELECT emp_salary INTO salary FROM employees WHERE id = emp_id;
  RAISE NOTICE 'Salary: %', salary;
END;
$ LANGUAGE plpgsql;

The tool produces side-by-side comparisons and detailed reports, giving teams the transparency they need to trust the process.

Post-Migration: Enterprise-Grade Performance on Azure

Once you’re on PostgreSQL, Azure provides a range of options to ensure performance, scale, and security.

Azure Database for PostgreSQL

  • v6-series compute SKUs: Scale vertically up to 192 vCores for high-throughput workloads.
  • Elastic clusters with Citus: Horizontal scaling for multi-tenant SaaS, IoT, and large-scale analytics.
  • SSD v2 storage: High IOPS and low latency.
  • Azure Monitor: Real-time insights and automated optimization.
  • Security: Microsoft Defender for Cloud, Entra ID integration, private endpoints, confidential compute, end-to-end encryption.

Azure HorizonDB (Private Preview)

For extreme workloads, Azure HorizonDB offers:

  • Up to 3,072 vCores and 128 TB of auto-scaling storage.
  • Sub-millisecond multi-zone commit latencies.
  • Up to 3x higher throughput than self-managed PostgreSQL.
  • Built-in AI model management and DiskANN advanced filtering.

And because it’s PostgreSQL-compatible, you can start with Azure Database for PostgreSQL today and migrate to HorizonDB later without replatforming.

Critical Considerations & Limitations

While the benefits are substantial, it’s important to be aware of potential pitfalls:

  • Complexity of stored procedures: Even with AI assistance, some Oracle-specific features (e.g., hierarchical queries, flashback) may require manual intervention.
  • Performance tuning: PostgreSQL’s query planner behaves differently. You may need to rewrite indexes and optimize queries post-migration.
  • Team training: Your DBAs and developers need time to learn PostgreSQL-specific tools and practices.
  • Tool maturity: The AI-assisted migration tool is still in preview. Expect some edge cases and plan for manual validation.

Recommendation: Start with a non-critical workload, validate thoroughly, and then scale to production.

Next Steps: Your Migration Roadmap

  1. Assess: Use the AI-assisted migration tool to analyze your Oracle schema and code.
  2. Plan: Identify dependencies, performance requirements, and security needs.
  3. Pilot: Migrate a low-risk application first.
  4. Optimize: Tune indexes, queries, and configuration for PostgreSQL.
  5. Scale: Leverage Azure Database for PostgreSQL or HorizonDB for production.

If you’re considering a move from Oracle to PostgreSQL, the tools and platform are ready. The question is: are you ready to lead?

Further Reading

Enterprise database server migration from Oracle to PostgreSQL on Azure Technical Structure Concept

This content was drafted using AI tools based on reliable sources, and has been reviewed by our editorial team before publication. It is not intended to replace professional advice.